Clonal multi-omics reveals Bcor as a negative regulator of emergency dendritic cell development.

Despite advances in single-cell multi-omics, a single stem or progenitor cell can only be tested once. We developed clonal multi-omics, in which daughters of a clone act as surrogates of the founder, thereby allowing multiple independent assays per clone. With SIS-seq, clonal siblings in parallel "sister" assays are examined either for gene expression by RNA sequencing (RNA-seq) or for fate in culture. We identified, and then validated using CRISPR, genes that controlled fate bias for different dendritic cell (DC) subtypes. This included Bcor as a suppressor of plasmacytoid DC (pDC) and conventional DC type 2 (cDC2) numbers during Flt3 ligand-mediated emergency DC development. We then developed SIS-skew to examine development of wild-type and Bcor-deficient siblings of the same clone in parallel. We found Bcor restricted clonal expansion, especially for cDC2s, and suppressed clonal fate potential, especially for pDCs. Therefore, SIS-seq and SIS-skew can reveal the molecular and cellular mechanisms governing clonal fate.

Deep Shave Removal of Suspected Basal Cell Carcinoma: A Prospective Study.

BACKGROUND: Diagnosis and treatment of basal cell carcinoma (BCC) in the same visit by shave removal may decrease health care spending and promote patient satisfaction. OBJECTIVE: To prospectively evaluate deep shave removal of lesions clinically suspicious for low-risk BCC on the trunk or extremities in immunocompetent patients. MATERIALS AND METHODS: Deep shave removal with the intent to remove the entire tumor was performed from January 2015 to June 2016, and patients were followed prospectively for clinical evidence of tumor recurrence. RESULTS: Seventy-seven lesions were removed from 51 patients, including 29 (37%) superficial and nodular BCCs, 27 (35%) superficial BCCs, 16 (21%) nodular BCCs, and 5 (6%) non-BCCs. Fifteen BCCs (21%) had positive residual margins after deep shave removal, which was significantly more likely to occur in nodular compared with superficial BCCs (odds ratio = 7.8, 95% confidence interval = 1.4-43), and underwent re-excision. Fourteen specimens initially reported to have negative margins after deep shave underwent resectioning, which revealed positive margins in 4 specimens (28.6%). No BCCs have recurred clinically after an average follow-up of 50 months (SE 3.2). CONCLUSION: Consider deep shave removal for low-risk BCCs on the trunk or extremities in immunocompetent patients hoping to avoid a second treatment visit.

In pursuit of biomarkers for predicting susceptibility to activity-based anorexia in adolescent female rats.

OBJECTIVE: Identifying risk factors that contribute to the development of anorexia nervosa (AN) is critical for the implementation of early intervention strategies. Anxiety, obsessive-compulsive behavior, and immune dysfunction may be involved in the development of AN; however, their direct influence on susceptibility to the condition remains unclear. Here, we used the activity-based anorexia (ABA) model to examine whether activity, anxiety-like behavior, compulsive behavior, and circulating immune markers predict the subsequent development of pathological weight loss. METHOD: Female Sprague-Dawley rats (n = 44) underwent behavioral testing before exposure to ABA conditions after which they were separated into susceptible and resistant subpopulations. Blood was sampled before behavioral testing and after recovery from ABA to screen for proinflammatory cytokines. RESULTS: Rats that were vulnerable to pathological weight loss differed significantly from resistant rats on all key ABA parameters. While the primary measures of anxiety-like or compulsive behavior were not shown to predict vulnerability to ABA, increased locomotion and anxiety-like behavior were both associated with the extent of weight loss in susceptible but not resistant animals. Moreover, the change in expression of proinflammatory markers IL-4 and IL-6 evoked by ABA was associated with discrete vulnerability factors. Intriguingly, behavior related to risk assessment was shown to predict vulnerability to ABA. DISCUSSION: We did not find undisputable behavioral or immune predictors of susceptibility to pathological weight loss in the ABA rat model. Future research should examine the role of cognition in the development of ABA, dysfunction of which may represent an endophenotype linking anorectic, anxiety-like and compulsive behavior. PUBLIC SIGNIFICANCE: Anorexia nervosa (AN) has among the highest mortality rates of all psychiatric disorders and treatment options remain limited in their efficacy. Understanding what types of risk factors contribute to the development of AN is essential for implementing early intervention strategies. This study describes how some of the most common psychological features of AN could be used to predict susceptibility to pathological weight loss in a well-established animal model.

COVID-19 vaccine safety and efficacy in patients with immune-mediated inflammatory disease: Review of available evidence.

Dermatologists diagnose and treat many immune-mediated inflammatory diseases (IMID). Understanding the inherent immune dysregulation of these diseases as well as the additional disruption that comes as a result of IMID treatments has been important during the COVID-19 pandemic. With vaccines becoming widely available, dermatologists need to be familiar with the risks and benefits of vaccination in these patients, particularly those taking biologics, in order to have informed discussions with their patients. In this review, we present the current evidence related to COVID-19 vaccine safety and efficacy in patients with IMID and review existing recommendations for vaccination against SARS-CoV-2. Given the current evidence, there is minimal concern that these patients are at any greater risk of harm from COVID-19 vaccination compared to healthy controls. For most, the benefit of avoiding severe COVID-19 through vaccination will outweigh the theoretical risk of these vaccines. A question that is still outstanding is whether patients on biologics will generate a sufficient immune response to the vaccine, which may be dependent on the specific biologic therapy and indication being treated. This underscores the importance of following patients with IMID after vaccination to determine the safety, efficacy, and duration of the vaccine in this population.

Dendritic cell subsets.

Dendritic cells (DC) are professional antigen presenting cells comprising a variety of subsets, as either resident or migrating cells, in lymphoid and non-lymphoid organs. In the steady state DC continually process and present antigens on MHCI and MHCII, processes that are highly upregulated upon activation. By expressing differential sets of pattern recognition receptors different DC subsets are able to respond to a range of pathogenic and danger stimuli, enabling functional specialisation of the DC. The knowledge of functional specialisation of DC subsets is key to efficient priming of T cells, to the design of effective vaccine adjuvants and to understanding the role of different DC in health and disease. This review outlines mouse and human steady state DC subsets and key attributes that define their distinct functions.

Daptomycin-resistant Staphylococcus aureus clinical isolates are poorly sensed by dendritic cells.

Methicillin-resistant Staphylococcus aureus (MRSA) presents an increasing threat to public health, with antimicrobial resistance on the rise and infections endemic in the hospital setting. Despite a global research effort to understand and combat antimicrobial resistance, less work has focused on understanding the nuances in the immunopathogenesis of clinical strains. In particular, there is a surprising gap of knowledge in the literature pertaining to how clinical strains are recognized by dendritic cells (DCs). Here, we show that the activation of DCs is compromised in response to MRSA strains resistant to the last-line antibiotic daptomycin. We found a significant reduction in the secretion of proinflammatory cytokines including tumor necrosis factor-α, interleukin-6, regulated upon activation, normal T cell expressed, and secreted and macrophage inflammatory protein-1ß, as well as decreased expression of CD80 by DCs responding to daptomycin-resistant MRSA. We further demonstrate that this phenotype is coincident with the acquisition of specific point mutations in the cardiolipin synthase gene cls2, and, partly, in the bifunctional lysylphosphatidylglycerol flippase/synthetase gene mprF, which are genes that are often mutated in clinical daptomycin-resistant strains. Therefore, throughout infection and antibiotic therapy, MRSA has the capacity to not only develop further antibiotic resistance, but also develop resistance to immunological recognition by DCs, because of single amino acid point mutations occurring under the selective pressures of both host immunity and antibiotic therapy. Understanding the diversity of clinical MRSA isolates and the nuances in their immune recognition will have important implications for future therapeutics and the treatment of these infections.

Sweet syndrome with pulmonary involvement in a patient with myelodysplastic syndrome.

We report a patient with Sweet syndrome involving the pulmonary system in the context of myelodysplastic syndrome. Although Sweet syndrome may involve a variety of organ systems, the pulmonary system is rarely affected and can result in poor clinical outcomes, including acute respiratory distress syndrome. Both cutaneous and pulmonary symptoms respond well to systemic corticosteroid therapy and early diagnosis and treatment can improve the prognosis. Our case highlights the importance of collaboration between hematologists, dermatologists, and pulmonologists to facilitate effective diagnosis, triage, and treatment of these patients.

Dysplastic nevi with severe atypia: Long-term outcomes in patients with and without re-excision.

BACKGROUND: Dysplastic nevi with severe atypia (severely dysplastic nevi [SDN]) are frequently re-excised because of the concern that these lesions may in fact represent early melanoma. Data on long-term follow-up of these patients are limited. OBJECTIVE: We sought to determine the rate of subsequent melanoma development in patients with SDN who underwent re-excision versus those who did not and to determine factors associated with decision to re-excise. METHODS: A retrospective single institutional study was conducted with 451 adult patients (mean age 41.3 years) with SDN biopsied between November 1994 and November 2004, with clinical follow-up of at least 5 years. RESULTS: In 451 patients with SDN, re-excision was performed on 36.6%. Two melanomas were diagnosed in the re-excision specimens. Subsequent metastatic melanoma developed in 7 patients, all of whom had a history of melanoma. Margin comments influenced decision to re-excise. LIMITATIONS: This was a retrospective study at a single institution. CONCLUSION: Re-excision of all SDN may not be necessary.

Multifocal primary cutaneous nodular amyloidosis.

Nodular cutaneous amyloidosis (NCA), the least common form of primary cutaneous amyloidosis, is characterized clinically by waxy, purpuric plaques and nodules and histologically by amyloid deposits in the dermis and subcutaneous tissue. We present a patient who developed multiple, non-contiguous NCA lesions over a three year period without evidence of systemic disease. We reviewed the literature and found few other cases of this unusual presentation.

Prevalence and impact of health-related internet and smartphone use among dermatology patients.

Health information is increasingly accessible via the Internet and smartphone applications (apps), and patients may perceive these resources as tools for self-education and/or self-diagnosis. The objective of this study was to assess the characteristics of dermatology patients who use the Internet and/or smartphone apps to access health information and to evaluate the impact that these resources have on patients' health care-seeking behavior and interactions with physicians. Online resources offer both opportunities and challenges for dermatologists. Because patients often consult online resources for information about dermatologic conditions and may rely on these resources instead of seeking the care of a dermatologist, it is important for dermatologists to be involved in the development of high-quality online content that educates the public while also emphasizing the need to seek in-person medical care.

RIPK3 controls MAIT cell accumulation during development but not during infection.

Cell death mechanisms in T lymphocytes vary according to their developmental stage, cell subset and activation status. The cell death control mechanisms of mucosal-associated invariant T (MAIT) cells, a specialized T cell population, are largely unknown. Here we report that MAIT cells express key necroptotic machinery; receptor-interacting protein kinase 3 (RIPK3) and mixed lineage kinase domain-like (MLKL) protein, in abundance. Despite this, we discovered that the loss of RIPK3, but not necroptotic effector MLKL or apoptotic caspase-8, specifically increased MAIT cell abundance at steady-state in the thymus, spleen, liver and lungs, in a cell-intrinsic manner. In contrast, over the course of infection with Francisella tularensis, RIPK3 deficiency did not impact the magnitude of the expansion nor contraction of MAIT cell pools. These findings suggest that, distinct from conventional T cells, the accumulation of MAIT cells is restrained by RIPK3 signalling, likely prior to thymic egress, in a manner independent of canonical apoptotic and necroptotic cell death pathways.

Synthetic 5-amino-6-D-ribitylaminouracil paired with inflammatory stimuli facilitates MAIT cell expansion in vivo.

Introduction: Mucosal-associated invariant T (MAIT) cells are a population of innate-like T cells, which mediate host immunity to microbial infection by recognizing metabolite antigens derived from microbial riboflavin synthesis presented by the MHC-I-related protein 1 (MR1). Namely, the potent MAIT cell antigens, 5-(2-oxopropylideneamino)-6-D-ribitylaminouracil (5-OP-RU) and 5-(2-oxoethylideneamino)-6-D-ribitylaminouracil (5-OE-RU), form via the condensation of the riboflavin precursor 5-amino-6-D-ribitylaminouracil (5-A-RU) with the reactive carbonyl species (RCS) methylglyoxal (MG) and glyoxal (G), respectively. Although MAIT cells are abundant in humans, they are rare in mice, and increasing their abundance using expansion protocols with antigen and adjuvant has been shown to facilitate their study in mouse models of infection and disease. Methods: Here, we outline three methods to increase the abundance of MAIT cells in C57BL/6 mice using a combination of inflammatory stimuli, 5-A-RU and MG. Results: Our data demonstrate that the administration of synthetic 5-A-RU in combination with one of three different inflammatory stimuli is sufficient to increase the frequency and absolute numbers of MAIT cells in C57BL/6 mice. The resultant boosted MAIT cells are functional and can provide protection against a lethal infection of Legionella longbeachae. Conclusion: These results provide alternative methods for expanding MAIT cells with high doses of commercially available 5-A-RU (± MG) in the presence of various danger signals.

The Influence of Antibiotic Resistance on Innate Immune Responses to Staphylococcus aureus Infection.

Staphylococcus aureus (S. aureus) causes a broad range of infections and is associated with significant morbidity and mortality. S. aureus produces a diverse range of cellular and extracellular factors responsible for its invasiveness and ability to resist immune attack. In recent years, increasing resistance to last-line anti-staphylococcal antibiotics daptomycin and vancomycin has been observed. Resistant strains of S. aureus are highly efficient in invading a variety of professional and nonprofessional phagocytes and are able to survive inside host cells. Eliciting immune protection against antibiotic-resistant S. aureus infection is a global challenge, requiring both innate and adaptive immune effector mechanisms. Dendritic cells (DC), which sit at the interface between innate and adaptive immune responses, are central to the induction of immune protection against S. aureus. However, it has been observed that S. aureus has the capacity to develop further antibiotic resistance and acquire increased resistance to immunological recognition by the innate immune system. In this article, we review the strategies utilised by S. aureus to circumvent antibiotic and innate immune responses, especially the interaction between S. aureus and DC, focusing on how this relationship is perturbed with the development of antibiotic resistance.